TBM Mary Ann, which was launched from Water Orton in June last year, has now built 2.8km of the twin-bore tunnel that will take trains into Birmingham as they approach Curzon Street Station in the heart of the city.
Driving at around 30m underground towards Washwood Heath in Birmingham, the TBM has excavated under the Park Hall Nature Reserve and River Tame and is now passing under Castle Vale. It will continue adjacent to and under the M6 motorway before breaking through at Washwood Heath early next year.
Operated by HS2 contractor Balfour Beatty Vinci (BBV), TBM Mary Ann is 125m long and weighs 1,600 tonnes. She was after named Mary Ann Evans – the real name of Warwickshire-born writer George Eliot.
The second TBM building the Bromford Tunnel was launched in March this year. The majority of TBM Elizabeth, including the gantries and the centre part of the cutterhead, have been reused from TBM Dorothy which completed the 1.6km twin-bore Long Itchington Wood Tunnel in Warwickshire last year.
TBM Elizabeth is named after Dame Elizabeth Cadbury who campaigned for the education and welfare of women in Birmingham.
Mary Ann and Elizabeth will install a total of 41,594 concrete segments, creating 5,942 rings to make the twin-bore tunnel. Each ring weighs 49 tonnes. The segments are being produced at BBV’s pre-cast factory at Avonmouth near Bristol.
